If you are coming to Asuncion, strongly consider staying at the Arthaus Boutique. It's about 5-10 minutes outside of "downtown" Asuncion, but as you'll find, there really isn't much in "downtown" Asuncion. Instead the area around Arthaus is a more upscale area with private homes, and walking distance to two major shopping areas, restaurants, and higher end spots. I highly recommend it over the main city area.
Javier the owner speaks perfect English. He was born in the States, I believe. He's tremendously helpful and has great stories. He helped me find someone to drive me around the country and give a private tour (in Spanish) and recommended one of the best restaurants I've ever eaten at. You're not going to find much tourist infrastructure in Paraguay, so it pays to know someone who can make good recommendations. Javier is that guy.
The hotel is a converted house slowly becoming a hotel. Its not overly flashy or fancy, you walk through an outside garden and up a winding staircase to get to your room. Though it provides what you need, is clean, and the internet is good.
If you're coming to Paraguay, I'd absolutely recommend staying here. It's worth it simply for the ability to talk with Javier, especially as an English speaker, it will take some of the barrier away from coming to one of the South American countries where English is not often spoken.